ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20031

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Scientific Objectives of SPARC*

and the Value of Data Assimilation

Alan O’Neill

Data Assimilation Research Centre

University of Reading

*Stratospheric Processes and their Role in Climate:

a project of the World Climate Research Programme

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Aim of SPARC

• To bring stratospheric expertise to bear on scientific issues concerned with climate processes and climate prediction;

• for the benefit of– World Climate Research Programme – WMO/UNEP Ozone Assessment– IPCC– Space Agencies

ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20032

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SPARC Stratospheric Processes and their Role in Climate

• Research project (est. 1992) of the WCRP.• Focuses on role of stratospheric dynamical,

chemical and radiative processes of the troposphere-stratosphere system:– Influence of stratosphere on climate

– Physics & chemistry of ozone depletion

– Stratospheric variability and monitoring

– Changes in UV radiation

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Web Site

http://www.aero.jussieu.fr/~sparc

ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20033

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1979-1994

2σ uncertainty

Compiled using radiosonde, satellite and analysed data sets

Mean vertical profile of annual & decadal temperature trend at 45oN.

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ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20034

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ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20035

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ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20036

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ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20037

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ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20038

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Stratospheric Chemistry

and Climate

Stratosphere-Troposphere coupling

Detection and Attribution of Past Stratospheric Changes

Model

Development

Process

StudiesData

Future Themes

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Stratospheric Chemistryand Climate

• How will stratospheric ozone and other constituents evolve?

• How will changes in stratospheric composition affect climate?

• What are the links between changes in stratospheric ozone, UV radiation and tropospheric chemistry?

ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 20039

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Ozone-trends and with Chemistry on condensed matter

T ropospher e

St ratosphere

Cl ClO

In-situ O3 destruction

CirrusprocessingForcing by

Weather Systems

Other DynamicalForcings Contributions from

polar processed air

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ASAPAssessment of Stratospheric Aerosol Processes

Aerosol Processes

Precursor Gases

Modeling

Trend Analysis

Aerosol Record

El Chichón Pinatubo

ASAP – The SPARC Aerosol Assessment

ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 200310

Long timescaleLong timescale

§Why does the AO tend to become negative after sudden warmings?

§How could this relationship be used to forecast the AO index?

§Is the effect confined to extreme events in the stratosphere, oris there a linear relationship between the stratospheric NAM and the future AO index?

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ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 200311

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SPARC Data Assimilation initiative

ESA-ESRIN, Frascati, Rome, Italy

18th – 29th August 200312

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Data Assimilation Working Grou

• Collect information on stratospheric data sets on meteorology and chemistry (quality, availability, software…).

• Process-focused quality assessments.• Collect and document information in

data assimilation systems.• Liaise with space and other agencies on

SPARC data needs.

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End